JEE MATHEMATICS MCQ: TRIGONOMETRIC EQUATIONS

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Analyzing +4 | -1

The number of roots of the equation

\sum\limits_{{k=1}}^7 \sin (k x)=7 \sin 4 x

in the interval

[0,2 \pi]

View answer and explanation

Correct option: D

The correct answer is D (9) because the equation simplifies to sin(4x) = 0 or cos(x) = 1, leading to 9 solutions in the interval [0, 2π].

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